Radio power pack



Patented July 9; 1929.

UNITED STATES,

, 1,720,221 PATENT-OFFICE.

ISIDOR KITSE'E, or PHILADELPHIA, PENNSYLVANIA.

RADIO rowan rAoK.

Application filed May 25,

My invention relates to an improvement in radio power packs. "I will describe here' my invention as applied to A eliminators, it being understood that substantially the same circuit may be used for B andC' eliminator-s, but it is obvious that transformers' ofqdiffereiit values have to be employed. In the accompanying drawing, which illus "tra'tes'rone form my invention may take, 1 and 2 are the circuit wires supposedly carryingan alternating current; 3 is the primary of a transformer; 4 and 5 the two secondaries thereof; The secondary 4 comprises here the two parts 6 and 7; 8 is the midtap 25 the stem adapted to seal the housing, this stem carries the necessary conductors, here after to be enumerated, p To the terminal conductors 11 and 12 of e secondary 5 are connected the conductors 30 l? and 18 going through the stem 16 into the housingld To these conductors l7 and 18 are; connected the filaments 19 and 20 in multiple arc.' The terminal 9 of the secondary 4'connects through the stem 21 with the complementary plate 22. The'terminal 10 of; the" secondary 4 connects through stem 23 with the complementary plate 24. To the lower terminal of the choke 13 is connected the conductor 25 in contact with stem 26 and Bio: to this stemis connected the filament 27.

Tothe jointure of '12 and 18, outside the housing, is connected the conductor 28; the choke coil 30 is connectedwith one terminal through 29 with 28 and with the other terminal to 31 adapted to be, connected to A plusterminal of the radio s a, Inshunt to 14 and'28 is connected the resistance32, the connection being indicated by dotted lines, as this shunt is onlyrequiredinextreme case's.

The secondary 4 supplies. the required energy to actuate the thermionic valves of a radio set and the two filaments'l9 and 20 with their complementary plates '22 and 24 AC. into D. C. The filament 27 acts as the act as the full wave rectifiers to convert the 1927. Serial No. 1s4,117.

filter for-the rectified current to smooth out the so-called ripples or inequalities of said I rectified current.

To eliminate all interference or so-called" hum I make use of the second choke coil, here designated by the numeral 13. In the employment of the two choke coils 13 and 30 I have foundin actual practice that it. is of great advantage to make the choke coils of different resistances and therefore different henries and for this reason all the sets made in accordance with this my invention have the coil 13 of a gauge lower than the coil 30 or ofa different number of convolutions, bu in practice the-different gauged wire suflices.

I have also found in practice that a smallcondenser, .25. microfaradscapacity over bridging the outer terminals 9' and 10 of the secondary 4-is. of some advantage with practical operation of the device and this small condenser may be connected to the points here indicated by XandY.

7 It should be noted that aside from this small condenser, which in'reality-is not an absolute necessity, no condensers or large resistances are employed in mysystem; The

I value of the little resistance 32 should not exceed .20 ohms and itscarrying capacity should be far less than ampere. In real ity the small condenser and little-resistance are only refinements and may be omitted without interfering with the operation of the device. i I I From the description and illustration of this system andits circuit the great advantage over existing systems and circuits lies not-only in the elimination of condensers and resistances but also in the elimination of' so-called filter cells, electrolytic or otherwise,

and the employment ofone housing embodying the entire rectifying and filtering means aswell as the different values of the choke coils when employed and in fact of the Whole. arrangement and conne'ctions of the differ out parts of the ciro uit';

It may not be amiss to state that a number of instrumentsmade'in accordance with this my inventionare successfully operat 'ing different types'of radio setsand are'en 'tirely free from the so-called hum or sim-f' ilarinterference. 1Q.

Having now ,desoribed my invention what I claim as new and desire to secureby Letters Patent 1s 1. In a radio: power pack a transformer having a main --s econdary and cathode heater secondary, a circuit connecting with one terminal to the center-tap of the secondary and with another terminal to oneterminal of the cathode heater secondary,

ondary, a center-tap for said secondary, a

cathode heater secondary, a rectifying tube for-full wave rectification, an auxiliary fila-' ment in said tube, said auxiliary filament connected \Vith-On6; terminal to the centertap of the power secondary and with the other terminal to one conductor of the cathode heater secondary.

3. In a radio power pack, a transformer having secondarywindings, a full Wave rec-- t'ifying tube, the anodes and cathodes thereof connected to their proper secondaries, a filter circuit for said power pack, said filter circuit comprising an a'uxiliary filament positioned in said rectifying tube and connected with one terminal to one side of the cathodesecondary and with the other ter-.

minal to the center-tap of the anode secondary, and lncluding a non-inductive resistance between said center-tap and said filament.

4. In the art of filtering a rectified ourrent useful for radio Work, the improvement which .consists in causing said rectified current to pass in part through a filament p0- part through comparatively small non-inductive resistance and choke coils.

In testimony whereof I affix my signature.

ISI DOR KITSEE.

sitioned in an evacuated envelope and in 

